Electric indicator



(No Model.)

C. WIRT.

ELECTRIC INDICATOR.

Patented Jan.20,1891.

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UNITED STATES PATENT OFFICE.

CHARLES WIRT, OF ORANGE, NEHV JERSEY.

ELECTRIC INDICATOR.

SPECIFICATION forming part of Letters Patent No. 444,966, dated January 20, 1891.. Application filed January 6, 1890. Serial No.386,0681 (No model.)

To all whom it may concern:

Be it known that 1, CHARLES \VIRT, a citizen of the United States, residing at Orange, in the county of Essex and State of New Jersey, have invented a certain new and useful Improvement in Electric Indicators, of which the following is a specification.

My invention relates to indicators for electric currents, and has for its object to provide a simple, cheap, and-easilyapplicable meter. It is illustrated in the accompanying drawin gs, wherein-- Figure 1 is a plan view of the device with the cover removed. Figs. 2, 3, and 4 are modifications of the armature and conductor carrying the current to be measured.

Like parts are indicated by the same letter in each figure.

A is the bed to which the parts are secured, B B portions of a conductor carrying the current to be measured, and O C the bindingposts or clamps by which these portions of the conductor are secured to the device, so as to bring that portion of the device or conductor which actuates the needle in series.

D is a conductor leading to the inside of the coil E, and F is a similar conductor lead ing to the outside of such coil by means of the binding-post G on one of the clamps H H, which hold the coil in position. It is to be understood, of course, that the base A is of insulating material.

J is an arm supported on and rising from i the plate K, and L is a shaft delicately pivoted on this plate and arm. To this shaft is secured the index or needle M, and also the armature N, shaped as shown. The index or needle and armature and shaft are thus fixed so as to rotate on an axis which is the center of an are formed by one end of the nearly elliptical coil. This coil is built up in any desired manner, as of sheets, strips, or wire. The armature is made of soft iron and the index or needle of some light material. The relation of armature and index or needle as to size and weight should be such as that when the device is in an operative position the index or needle points to the zeroqnark of the scale 0, and this relation may be such that in this event the armature will stand in substantially the position indicated in Fig. 1.

In Fig. 2 the conductor B is simply a bar with an arc-shaped notch B therein, concentric with which are journaled the shaft lb and armature N.

In Fig. 3 the conductor 13 assumes the form of a flat strip with the curved portion B the modified armature B and a pivoted needle B, on which such armature is secured.

In Fig. i the conductor 13 is simply provided with a curve B at the center of which is pivoted the needle. The form of the coil convo lution or curve of the conductor could of course be greatly altered, the essential feature being that such conductor or connected device should present a curve at some point along which a curved armature may move in such manner that the opposed surfaces of the armature and curve are substantially parallel.

during such motion and at a constant distance. Obviously a curve and armature projected on arcs of concentric circles would be the natural form by which to secure the desired result. Moreover, it is equally apparent that the armature may be placed either within or without the curve of the conductor. It is gravity which holds the needle at the zeropoint when the device is out of operation; but of course it is immaterial what force is brought into requisition to hold the needle at zero normally and to oppose the motive power of the current when applied. By varying the character of the conductor or coil at its point of curvature substantially the same form of device can be applied either as a voltmeter or ammeter. As the current increases in volume or pressure the needle moves toward the higher indication, and thus more and more of the surface of the armature is brought into proximity with the effective surface of the coil. In this form of device the scale begins at zero and registers every fluctuation until the maximum capacity of the meter is reached.

The use and operation of my invention, briefly stated,are as follows: The coil or curved portion or effective part of the conductor is coupled in series with the conductor proper carrying the current to the meter, and the device is fixed in position so as to bring the needle to the zero-point. If now the current be applied, the armature tends to move so as to bring more and more of its surface into proximity with the effective surface of the curved conductor, and thus the needle is carried over the scale to indicate the higher readings.

I claim 5 1. The combination of a conductor, an armature suspended in proximity thereto, and an indicator operated by such armature, said armature free to move only so that each point of its effective surface traverses a path equixo distant from that of the current at the effective portion of the conductor.

2. The combination of a conductor and armature similarly curved, and an indicator operated by such armature, which is suspended 15 so thatthe opposed points on the effective surfaces of the curve are substantially constantly equidistant.

3. The combination of a conductor-coil having in part the form of a cylindrical surface, the remaining portion having some form in- 20 closing more volume than the said imaginary cylinder, with a movable armature curved to a substantially cylindrical form and pivoted on a line which is substantially the axis of the curved part of the cylindrical portion of 25 the coil and armature.

CHARLES \VIRT.

Witnesses:

FREDERICK EGNER, VILLIAM REEVES. 

